/Engine/Source/Runtime/Engine/Classes/PhysicsEngine/BodySetup.h
Given a location in body space, and face index, find the UV of the desired UV channel. Note this ONLY works if 'Support UV From Hit Results' is enabled in Physics Settings.
bool CalcUVAtLocation ( const FVector & BodySpaceLocation, int32 FaceIndex, int32 UVChannel, FVector2D & UV ) const